In sinus tachycardia, which P wave characteristic may be visible on the ECG rhythm strip?

In sinus tachycardia, the heart rate exceeds the normal range, typically over 100 beats per minute while maintaining the sinus rhythm. One characteristic that can be observed on an ECG during this condition is that the P waves may be superimposed on the proceeding T-wave. This happens because, at an increased heart rate, the intervals between heartbeats are shortened. As a result, the P wave, which represents atrial depolarization, can occur so close to the T-wave of the preceding heartbeat that they overlap.

The overlap can make it difficult to distinctly visualize the P wave, and this characteristic is significant in recognizing sinus tachycardia on an ECG. It is crucial for practitioners to identify such nuances, especially in rapid heart rate scenarios, as it provides insight into the underlying rhythm and help with diagnosis and management.